19nov09 oscillations from bias box

20no09

Links:

Intro:

When alfa was reinstalled in nov09, oscillations
were seen in the output signal. These were traced to the bias box. Part
of the "work" done on alfa was to move the capacitors in the bias lines
from inside the dewar to outside. This may have affected the bias
circuit causing the oscillations (or maybe they were there before at a
lower level).

On 19nov09 we transmitted a sine wave from the
control room to see if the 2.5 MHz oscillation frequency would mix with
our sine wave. The setup was: